Starter gear



Dec; 5, 1933. s. SHELDRICK STARTER GEAR Filed Oct. 22, 1930 INVENTOR. f. 5. JW

ATTORNEY.

Patented Dec. 5, 1 933 UNITED STATES PATENT OFFICE.

I 8 Claims. (01. 74-4) The object of my invention is to provide a starter gear of simple, durable and inexpensive construction.

A further object of my invention is to provide a starter gear especially adapted for use on automobiles,. which gear willbe suitable for .opera. tively connecting the starting motor and the engine.- A novel feature of my improved deviceis that when the starting motor pedal is pressed the 1 starting pinion is manually drawn into engage-. ment with the flywheel ring gear. The torque of the starting motor then holds the pinion in mesh withthis gear until the engine starts. The pinion operating device first actuates the pinion and i onfurthe'r application of the starting pedal draws back out of the way so that the'pinion may be automatically thrown out of engagement when the engine starts, irrespectiveof the manually shifting means.

My improved pinion is resiliently held in its inoperative position after being thrown out by the V flywheel ring gear and will remain-in this posi-i tion until the starting'motor pedal is again pressed to start the engine.

It-frequently happens, when the car is being started in cold weather, that the engine will fire with sumoient force to disengage the ordinary inertia type starting motor pinion but'still will not have sufiicient force to continue rotating past the next explosion'of the motor. The starting motor pinion in this case then continues to re volve in its disconnected position without further cranking the engine. The operatorof the car must then release his foot from the starting comes to rest atwhich time the pedal may again be depressed to again crank the engine. If the operator does not wait until the starting motor has stopped rotating, sufficient inertia will not be present to engage the starting motor pinion with the flywheel. This is a very annoying objection to the inertia type starting motor pinion and one which is fully overcome by the applicants device.

In myimproved structure the starting motor pinion is manually shifted into engagement with the engine flywheel and the shifting device drawn .outof the way before the starting motor is operated. If, when the engine first kicks over it throws the starting pinion out of engagement and then stalls, the starting pedal may be instantly released and then immediately depressed even though the starting motor is still rotating which subsequent depressing will again engage the starting motor pinion with the flywheel without the appreciable wait required under these conditions by the inertia type starter gear.

Still a further object of my invention is to provide a starting gear having the positive engaging 6 action of manually operable gears combined with the instantly disengaging action of the automatic type starting gears. Thus,.I am enabled to ob tain the desirable features of both of the above mentioned gears in one device, which device is cheap to manufacture, positive in operation and should easily last for the life of the car.

With these and other objects in view, my invention consists in the arrangement, construction and combination of thevarious parts of my improved deviceQas described in the specification, claimed in my claims, and illustrated in the accompanying drawing, among, which:

Figure 1 shows a broken away sectional view of a starting motor having my improved starting gear incorporated therewith.

Figure 2 shows an enlarged vertical central sec- I tional view of my improved starting gear while in itsengaged position.

Figure 3 shows a top view of my improved start I ing motor gear, and p v Figure'4 shows a sectional view taken on the line 44 of Figure 2.

' Referring to the accompanying drawing, I have used the reference numeral 10 to indicate an engine flywheel housing in which a conventional flywheel 11 is rotatably mounted. This flywheel is provided with a ring gear 12 around its periphery with which my improved starting gear meshes to crank the engine. The ring gear 12 is provided with a plurality of spiral teeth 13 machined therein, the spiral direction of the teeth being governed by the desired direction of rotation of the engine. e

The starting motor upon which my improved starting gear is mounted consists of a tubular shell 14 which is fastened to a flange 15, this flange forming the rear end of the starting motor. The flange 15 is fastened to the flywheel housing 10 by suitable capscrews 16 to hold the motor in place. The center portion of the flange 15 is dished so that it projects into-the flywheel housing and a bearing 1'7 is formed in the center of this dishedin portion to rotatably receive one end of an armatureshaft 18. A conventional armature 19 is fixedly secured to the shaft 18, which armature is electrically rotated in the ordinarymanner.

A starting motor switch 20 is fastened to the upper side of the shell 14, which switch is operated by a push rod 21, which extends upwardly through the floor boards of the car where a button 22 is fastened thereto in position to be operated by the drivers foot. When the button 22 is fully depressed it actuates the switch 23 in the conventional manner thereby operating the starting motor until the starter button is released. A transverse pin 23 extends through the intermediate portion of the push rod 21 and a compression spring 24 is disposed between the switch 20 and the pin 23 so that the push rod is resiliently urged at all times to its disengaged position.

The armature shaft 18 is provided with a splined portion 25 adjacent to the armature 19 and spaced from the bearing 17 upon which portion a correspondingly splined sleeve 26 is reciprocally mounted. lhe forward end of the sleeve 26 is formed integrally with a starting motor pinion 27, the teeth on the pinion being suitably spiraled to mesh with the spiral ring gear 12. The pinion 27 is supported on that portion of the armature shaft 18 between the bearing 17 and the end of the splines 25 so that the pinion is exactly centered independently of the splines 25 to perfectly mesh with the ring gear 12.

A U-shaped spring 29 is secured to the shaft 18 between the forward end of the splines 25 and the rear end of the armature, which spring is so tensioned that when the pinion is reciprocated to its disengaged position the spring will engage an annular notch 30 formed in the sleeve 26 thereby resiliently holding the pinion in this position.

. That section of the sleeve 26 lying between the notch 30 and the pinion 27 is provided with an r j annular trapezoidal groove 31 witl'l which suitable is forked at 34 to straddle a dog 35which'is pivotally mounted at 36 in the forked end of the lever.

' The dog 35 extends substantially parallel to the is engaged in the groove 31.

shaft 18 and the end of the dog, adjacent to the armature 19, is provided with a hook 37. A spring 38, interposedbetween the opposite end of the dog and the lever 32 resiliently urges dog into position where the hook 3'7 enters the groove 31'.

Referring to Figure 1, the disengaged position of the starter gear is shown wherein the hook 37 When the lever 32 is pushed downwardly or around the pivot 33 in a counterclock-wise direction, the pinion 27 and sleeve 26 will be shifted on the splines 25 into engagement with the ring gear teeth 13 by means of the hook 37 and groove 31. However, when the lever 32 is pivoted still further the outer end 39 of the dog 35 strikes against the flywheel housing 10 so that further movement of the lever pivots the dog around the pivot 36 thereby raising the hook 3'7 out of engagement with the groove 31 against the urging of the spring 38. This latter position is shown by the solid lines in Figure 2 and by the dotted lines 40, in Figure l which illustrates the position which the starting motor pinion and manually shifting device assumes when the engine is being cranked by the starting motor.

The upper end of the lever 32 is provided with an eye 11 through which the push rod 21 extends, and a coil spring 42 bears against this eye to resiliently urge the lever against the pin 23. The upper end of the spring 42 is anchored to the rod 21 just beneath the floor boards of the car so that when the button 22 is depressed the lever 32 is resiliently urged to pivot around the pivot 33. The reason for not positively pivoting the lever 32 is that occasionally the starting motor pinion will assume a position where its teeth will bear against the ends of the ring gear teeth 13 thereby preventing shifting of the pinion and consequently preventing operation of the lever.

Under such conditions it is necessary to depress the push rod 21 sufficient to start the starting motor thereby allowing the pinion to snap into mesh with the ring gear, due to the action of the spring 42.

To operate my improved device, the button 22 is pressed, thereby drawing the pinion 27 into engagement with the flywheel. A further depression of this button moves the dog 35 into a position where the hook 37 is drawn clear from the groove 31. Still further depressing the button 22 operates the switch 20 to start the starting motor. The hand of the spiral teeth on the pinion and ring gear is so chosen that the torque of the starting motor tends to hold the pinion into engagement during the cranking operation. When the engine starts under its own power an end thrust due to the spiral teeth is impressed on the pinion 27 suflicient to immediately shift it out of engagement and back to the inoperative position, shown in Figure 1, where the spring 29 then resiliently holds the pinion in this position. The starting motor may continue to revolve with the pinion in the above described inoperativeposb tion if the button 22 is still held in its depressed position. However, when the pedal is released the switch 20 is first disconnected and'then the lever 32 allowed to return toits upper position at which time the dog 35 is again resiliently urged by the spring 38 to position where the hook 37 3 engages the groove 31, thus resetting the device for a subsequent operation of the starting motor.

It will be apparent that even though the pinion is rotating while in its inoperative'position, due to the inertia of the armature 19, it may be shifted into engagement with the ring gear to re-start the engine. This is an advantage over the inertia type starter gear when cranking an engine in very cold weather. Another advantageous feaure in connection with this device is the means whereby the pinion is drawn manually into engagement with the ring gear and then the drawing means released from the pinion before the starting motor is operated to thus free the pinion so that it may bethrown out of engagement by engine flywheel when the engine starts due to the action of the spiral teeth thereon.

Some changes may be made in the arrangement, construction, and combination of the various parts of my improved device without departing from the spirit of my invention, and it is my intention to cover by my claims such changes as may reasonably be included within the scope thereof. 7

I claim as my invention:

1. In a device for manually shifting a starting pinion into mesh with a ring gear, a fixed stop associated with said device, means manually shiftable in a path substantially parallel to the axis of said pinion, and a dog centrally pivoted to said shifting means having one end thereof resiliently urged into engagement with said pinion so as to shift same into meshduring the first part of the movement of said means and the other end thereof in position to engage said fixed stop therebypivoting said dog out of engagement with said pinion when said shifting means is moved through its full range to thereby allow said pinion to be thrown out of mesh independently of said dog. 250

2. In a device for manually shifting a starting pinion into mesh with a ring gear, a shiftable dog adapted to move in a path substantially parallel to the axis of saidpinion, means for resiliently urging said dog into engagement with said pinion during the first portion of its shifting movement to thereby shift, the pinion into mesh with said gear, and means for forcing said dog out of said engagement against said resilient means during the remaining portion of said shifting movement to thereby allow said pinion to be thrown out of mesh independently of said dog.

3. In a device of the character described, an engine flywheel having-a ring gear thereon, a

starting motor armature shaft disposed adjacent to said ring gear, a pinion shiftably and nonrotatably mounted on said shaft, a switch for said starting motor, a rigid stop associated with said device, means for operating said switch, a lever pivotally mounted in said device having one end actuated by said operating means and the other end disposed adjacent to said pinion, and a dog pivotally mounted on thepinion end of said lever in position so that during the first portion of the actuating movement of the lever one end of saiddog will shift said pinion into engagement with said ring gear and during the remaining portion of said movement the other end of the dog will coact with said stop and be thereby forced out of engagement with said pinion to allow said pinion to be otherwise returned to its inoperative position.

4. In a device of the character described, an

engine flywheel having a ring gear thereon, a.

starting motor housing, a starting motor armature shaft disposed in said housing adjacent to said ring gear, a pinion shiftably and non-rotatably mounted on said shaft, a switch for said starting motor, means for operating said switch, a lever pivotally mounted in said device having one end actuated by the operating means andthe other end disposed adjacent tosaid pinion, and a dog pivotally mounted on the pinion end of said lever in position so that during the first portion of the actuating movement of the lever one end of the dog will shift said pinion into engagement with said ring gear andduring the remaining portion of said movement the other end of the dog will coact with said housing and be thereby forced out of engagement with the pinion to allow said pinion to be otherwise returned to its inoperative position.

5. Ina device of the character described, an engine flywheel having a ring gear thereon, a starting motor having a driving shaft disposed adjacent to said ring gear, a pinion shiftably and non-rotatably mounted on said shaft, a switch for said starting motor, means for operating said switch, a rigid stop associated with said device, a lever pivotally mounted upon said device having one end actuated by said switch operating means and the other end disposed adjacent to said pinion, and a dog pivotally mounted on the pinion end of said lever which dog is held in position so that during the first portion of the actuating movement of the lever the dog will shift said pinion into engagement with said ring gear and during the remaining portion of said movement the dog will coact with said stop and be thereby forced out of shifting position with said pinion so as to allow said pinion to be otherwise returned to its inoperative position.

6. A device, as claimed in claim 5, wherein said lever is resiliently actuated by said switch operating means.

7. A device, as claimed in claim 5, wherein said dog is resiliently urged to position upon said lever wherein it coacts with said pinion.

8. In a device of the character described, an engine flywheel having a spiral ring gear thereon, a starting motor having an armature shaft disposed adjacent to said ring gear, a spiral pinion shiftably and non-rotatably mounted on said shaft, a switch for said starting motor, a rigid stop associated with said device, a push rod for actuating said switch, a lever pivotally mounted intermediate of its ends on said device having one end resiliently actuated through a compression spring by said push rod and the other end disposed adjacent to said pinion, and a dog pivotally mounted on the'pinion end of said lever which dog is held in position so that during the first portion of the movement of the push rod said dog will shift said pinion into engagement with said ring gear and during the remaining portion of said movement the dog will coact with said stop and be thereby forced out of engage- LAURENCE S. SHELDRICK. 

